Protein Expression and Purification, Vol.101, 157-164, 2014
Purification and characterization of bioactive his(6)-tagged recombinant human tissue inhibitor of metalloproteinases-1 (TIMP-1) protein expressed at high yields in mammalian cells
Tissue inhibitor of metalloproteinases-1 (TIMP-1) is an endogenous inhibitor of matrix metalloproteinases (MMPs) with reported tumor promoting, as well as inhibitory, effects. These paradoxical properties are presumably mediated by different biological functions, MMP-dependent as well as -independent, and probably related to TIMP-1 levels of protein expression, post-translational modifications, and cellular localization. TIMP-1 is an N-glycosylated protein that folds into two functional domains, a C- and an N-terminal domain, with six disulfide bonds. Furthermore, TIMP-1 is processed in the N-terminal sequence. These three biochemical properties make TIMP-1 difficult to produce in conventional bacterial, insect, or yeast expression systems. We describe here a HEK293 cell-based strategy for production and purification of secreted and N-glycosylated recombinant his(6)-tagged human TIMP-1 (his(6)-rTIMP-1), which resulted in large amounts of highly purified and bioactive protein. Matrix-assisted laser desorption ionization mass spectrometry confirmed the N- and C-termini of his(6)-rTIMP-1, and N-glycosylation profiling showed a match to the N-glycosylation of human plasma TIMP-1. The his(6)-rTIMP-1 was bioactive as shown by its proper inhibitory effect on MMP-2 activity, and its stimulatory effect on cell growth when added to the growth medium of four different breast cancer cell lines. This study provides an easy set-up for large scale production and purification of bioactive, tagged recombinant human TIMP-1, which structurally and functionally is similar to endogenous human TIMP-1, while using an expression system that is adaptable to most biochemical and biomedical laboratories including those that do not perform protein purifications routinely. (C) 2014 Elsevier Inc. All rights reserved.
Keywords:Tissue inhibitor of metalloproteinase-1 protein;His tagged;Bioactive;HEK293E expression system